//gcc lock_test.c -lpthread
#include <stdio.h>
#include <unistd.h>
#include <pthread.h>

int num = 0; //设置为全局变量，在全局区域，共享

void* myfun(void* arg);

int main()
{
    pthread_t id[2];
    for (int i = 0; i < 2; i++) {
        pthread_create(&(id[i]), NULL, myfun, NULL);
 //   	printf("%d : %d \n", num,pthread_self());
    }
    pthread_join(id[0],NULL);
    pthread_join(id[1],NULL);
    printf("%d\n",num);
    return 0;
}

void* myfun(void* arg)
{
    int i;
    for(i=0;i<100000000;i++){
    	num++;
//    	printf("%d : %d \n",num,pthread_self());	
    }
    
    return NULL;
}
